Heat pump refrigerant loop arrangements

ABSTRACT

A heat pump includes a refrigerant loop. The refrigerant loop includes a compressor, a first condenser, a vapor generator having a first region and a second region, a first expansion valve, a second expansion valve, and a first evaporator. A branching point is positioned between the first condenser and the vapor generator. The branching point diverts a portion of a first heat exchange fluid circulating through the refrigerant loop to the vapor generator. The first expansion valve is positioned between the branching point and the vapor generator. An outlet of the vapor generator is coupled to a mid-pressure inlet port of the compressor.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. patentapplication Ser. No. 17/357,149 filed Jun. 24, 2021, entitled “HEAT PUMPREFRIGERANT LOOP ARRANGEMENTS.” The aforementioned related applicationis hereby incorporated by reference in its entirety.

FIELD OF THE DISCLOSURE

The present disclosure generally relates to heat pumps. Morespecifically, the present disclosure relates to refrigerant looparrangements for heat pumps.

BACKGROUND OF THE INVENTION

Heat pumps have been employed in vehicles. A refrigerant loop can beincluded in such heat pumps.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention, a heat pumpincludes a refrigerant loop. The refrigerant loop includes a compressor,a first condenser, a vapor generator, a first receiver-dryer, a firstbranching point, a first expansion valve, a first evaporator, a secondexpansion valve, and a heat exchanger. The first condenser is positioneddownstream of the compressor and coupled to an outlet port of thecompressor. The vapor generator is positioned downstream of the firstcondenser. The vapor generator includes a first region having a firstinlet and a first outlet and a second region having a second inlet and asecond outlet. The vapor generator receives a first heat exchange fluid.The first receiver-dryer is positioned between the first condenser andthe vapor generator. The first branching point is positioned between thefirst condenser and the vapor generator. The first branching pointdiverts a portion of the first heat exchange fluid circulating throughthe refrigerant loop to a first inlet of the vapor generator. The firstexpansion valve is positioned between the first branching point and thefirst inlet of the vapor generator. A first outlet of the vaporgenerator is coupled to a mid-pressure inlet port of the compressor. Thefirst evaporator is positioned downstream of the vapor generator andcoupled to a second outlet of the vapor generator. The second expansionvalve is positioned between the first evaporator and the vaporgenerator. The first evaporator is upstream of the compressor and iscoupled to a low-pressure inlet port of the compressor. The heatexchanger has a first region and a second region. The first region ofthe heat exchanger is positioned between the second outlet of the vaporgenerator and the second expansion valve. The first region of the heatexchanger is plumbed in series with the second region of the vaporgenerator such that an inlet of the first region of the heat exchangeris directly coupled to an outlet of the second region of the vaporgenerator.

Embodiments of the first aspect of the invention can include any one ora combination of the following features:

-   -   an inlet of the second region of the heat exchanger is        positioned downstream of the first evaporator;    -   an outlet of the second region of the heat exchanger is        positioned upstream of the low-pressure inlet port of the        compressor;    -   a second evaporator is positioned downstream of the vapor        generator and coupled to the second outlet of the vapor        generator;    -   the second evaporator is plumbed in parallel to the first        evaporator;    -   a third expansion valve is positioned between the second        evaporator and the vapor generator;    -   the third expansion valve is plumbed in parallel with the second        expansion valve;    -   an inlet of the second region of the heat exchanger is        positioned downstream of the second evaporator;    -   a bypass loop that includes an inlet and an outlet, where the        bypass loop is configured to bypass the second region of the        heat exchanger;    -   the inlet of the bypass loop is positioned immediately upstream        of the second region of the heat exchanger;    -   the outlet of the bypass loop is positioned immediately upstream        of the low-pressure inlet port of the compressor;    -   the bypass loop includes a shutoff valve positioned between the        inlet of the bypass loop and the outlet of the bypass loop;    -   an auxiliary refrigerant loop where the auxiliary refrigerant        loop includes an auxiliary compressor; an auxiliary condenser        positioned downstream of the auxiliary compressor and coupled to        an outlet port of the auxiliary compressor; an auxiliary        expansion valve positioned downstream of the auxiliary        condenser; and an auxiliary evaporator positioned downstream of        the auxiliary expansion valve and coupled to the auxiliary        expansion value, where the auxiliary evaporator is upstream of        the auxiliary compressor and coupled to a low-pressure inlet        port of the auxiliary compressor; and    -   an auxiliary receiver-dryer positioned downstream of the        auxiliary condenser, where the auxiliary receiver-dryer is        positioned upstream of the auxiliary evaporator.

According to a second aspect of the present disclosure, a heat pumpincludes a refrigerant loop. The refrigerant loop includes a compressor,a first condenser, a vapor generator, a first receiver-dryer, a firstbranching point, a first expansion valve, a first evaporator, a secondexpansion valve, a heat exchanger, a second evaporator, and a thirdexpansion valve. The first condenser is positioned downstream of thecompressor and coupled to an outlet port of the compressor. The vaporgenerator is positioned downstream of the first condenser. The vaporgenerator includes a first region having a first inlet and a firstoutlet and a second region having a second inlet and a second outlet.The vapor generator receives a first heat exchange fluid. The firstreceiver-dryer is positioned between the first condenser and the vaporgenerator. The first branching point is positioned between the firstcondenser and the vapor generator. The first branching point diverts aportion of the first heat exchange fluid circulating through therefrigerant loop to a first inlet of the vapor generator. The firstexpansion valve is positioned between the first branching point and thefirst inlet of the vapor generator. A first outlet of the vaporgenerator is coupled to a mid-pressure inlet port of the compressor. Thefirst evaporator is positioned downstream of the vapor generator andcoupled to a second outlet of the vapor generator. The second expansionvalve is positioned between the first evaporator and the vaporgenerator. The first evaporator is upstream of the compressor and iscoupled to a low-pressure inlet port of the compressor. The heatexchanger has a first region and a second region. The first region ofthe heat exchanger is positioned between the second outlet of the vaporgenerator and the second expansion valve. The first region of the heatexchanger is plumbed in series with the second region of the vaporgenerator such that an inlet of the first region of the heat exchangeris directly coupled to an outlet of the second region of the vaporgenerator. An inlet of the second region of the heat exchanger ispositioned downstream of the first evaporator. An outlet of the secondregion of the heat exchanger is positioned upstream of the low-pressureinlet port of the compressor. A second evaporator is positioneddownstream of the vapor generator and coupled to the second outlet ofthe vapor generator and is plumbed in parallel to the first evaporator.An inlet of the second region of the heat exchanger is positioneddownstream of the second evaporator. A third expansion valve ispositioned between the second evaporator and the vapor generator and isplumbed in parallel to the second expansion valve.

Embodiments of the second aspect of the present disclosure can includeany one or a combination of the following features:

-   -   a bypass loop having an inlet and an outlet where the bypass        loop is configured to bypass the second region of the heat        exchanger and where the inlet of the bypass loop is positioned        immediately upstream of the second region of the heat exchanger;    -   the outlet of the bypass loop is positioned immediately upstream        of the low-pressure inlet port of the compressor;    -   the bypass loop includes a shutoff valve positioned between the        inlet of the bypass loop and the outlet of the bypass loop;    -   an auxiliary refrigerant loop that includes an auxiliary        compressor; an auxiliary condenser downstream of the auxiliary        compressor and coupled to an outlet port of the auxiliary        compressor; an auxiliary expansion valve positioned downstream        of the auxiliary condenser; and an auxiliary evaporator        downstream of the auxiliary expansion valve and coupled to the        auxiliary expansion value, where the auxiliary evaporator is        upstream of the auxiliary compressor and coupled to a        low-pressure inlet port of the auxiliary compressor; and    -   an auxiliary receiver-dryer positioned downstream of the        auxiliary condenser, where the auxiliary receiver-dryer is        positioned upstream of the auxiliary evaporator.

These and other aspects, objects, and features of the present disclosurewill be understood and appreciated by those skilled in the art uponstudying the following specification, claims, and appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a schematic representation of a refrigerant loop arrangement,illustrating various components for exchanging heat within a heat pump,according to one example;

FIG. 2 is a schematic representation of the refrigerant looparrangement, illustrating a first condenser and a second condenser,according to one example;

FIG. 3 is a schematic representation of the refrigerant looparrangement, illustrating various component for exchanging heat withinthe heat pump, according to one example;

FIG. 4 is a schematic representation of the refrigerant looparrangement, illustrating a heater coupled to an accumulator, accordingto one example;

FIG. 5 is a schematic representation of the refrigerant looparrangement, illustrating a first evaporator and a second evaporator,according to one example;

FIG. 6 is a schematic representation of the refrigerant looparrangement, illustrating the first condenser, the second condenser, thefirst evaporator, the second evaporator, and the heater coupled to theaccumulator, according to one example;

FIG. 7 is a schematic representation of the refrigerant looparrangement, illustrating a vapor generator and a heat exchanger plumbedin series, according to one example;

FIG. 8 is a schematic representation of the refrigerant looparrangement, illustrating the vapor generator with first, second, andthird regions, according to one example;

FIG. 9 is a schematic representation of the refrigerant looparrangement, illustrating a bypass loop having a bypass heat exchanger,according to one example;

FIG. 10 is a schematic representation of the refrigerant looparrangement, illustrating the bypass loop having the bypass heatexchanger, according to another example; and

FIG. 11 is a schematic representation of the refrigerant looparrangement, illustrating an auxiliary refrigerant loop plumbed inseries with the refrigerant loop, according to another example.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

For purposes of description herein, the terms “upper,” “lower,” “right,”“left,” “rear,” “front,” “vertical,” “horizontal,” and derivativesthereof shall relate to the concepts as oriented in FIG. 1 . However, itis to be understood that the concepts may assume various alternativeorientations, except where expressly specified to the contrary. It isalso to be understood that the specific devices and processesillustrated in the attached drawings, and described in the followingspecification are simply exemplary embodiments of the inventive conceptsdefined in the appended claims. Hence, specific dimensions and otherphysical characteristics relating to the embodiments disclosed hereinare not to be considered as limiting, unless the claims expressly stateotherwise.

The present illustrated embodiments reside primarily in combinations ofmethod steps and apparatus components related to a heat pump.Accordingly, the apparatus components and method steps have beenrepresented, where appropriate, by conventional symbols in the drawings,showing only those specific details that are pertinent to understandingthe embodiments of the present disclosure so as not to obscure thedisclosure with details that will be readily apparent to those ofordinary skill in the art having the benefit of the description herein.Further, like numerals in the description and drawings represent likeelements.

As used herein, the term “and/or,” when used in a list of two or moreitems, means that any one of the listed items can be employed by itself,or any combination of two or more of the listed items, can be employed.For example, if a composition is described as containing components A,B, and/or C, the composition can contain A alone; B alone; C alone; Aand B in combination; A and C in combination; B and C in combination; orA, B, and C in combination.

In this document, relational terms, such as first and second, top andbottom, and the like, are used solely to distinguish one entity oraction from another entity or action, without necessarily requiring orimplying any actual such relationship or order between such entities oractions. The terms “comprises,” “comprising,” or any other variationthereof, are intended to cover a non-exclusive inclusion, such that aprocess, method, article, or apparatus that comprises a list of elementsdoes not include only those elements but may include other elements notexpressly listed or inherent to such process, method, article, orapparatus. An element proceeded by “comprises . . . a” does not, withoutmore constraints, preclude the existence of additional identicalelements in the process, method, article, or apparatus that comprisesthe element.

As used herein, the term “about” means that amounts, sizes,formulations, parameters, and other quantities and characteristics arenot and need not be exact, but may be approximate and/or larger orsmaller, as desired, reflecting tolerances, conversion factors, roundingoff, measurement error and the like, and other factors known to those ofskill in the art. When the term “about” is used in describing a value oran end-point of a range, the disclosure should be understood to includethe specific value or end-point referred to. Whether or not a numericalvalue or end-point of a range in the specification recites “about,” thenumerical value or end-point of a range is intended to include twoembodiments: one modified by “about,” and one not modified by “about.”It will be further understood that the end-points of each of the rangesare significant both in relation to the other end-point, andindependently of the other end-point.

The terms “substantial,” “substantially,” and variations thereof as usedherein are intended to note that a described feature is equal orapproximately equal to a value or description. For example, a“substantially planar” surface is intended to denote a surface that isplanar or approximately planar. Moreover, “substantially” is intended todenote that two values are equal or approximately equal. In someembodiments, “substantially” may denote values within about 10% of eachother, such as within about 5% of each other, or within about 2% of eachother.

As used herein the terms “the,” “a,” or “an,” mean “at least one,” andshould not be limited to “only one” unless explicitly indicated to thecontrary. Thus, for example, reference to “a component” includesembodiments having two or more such components unless the contextclearly indicates otherwise.

Referring to FIGS. 1-11 , a heat pump 20 includes a refrigerant loop 24.The refrigerant loop 24 includes a compressor 28, a first condenser 32,a vapor generator 36, a branching point 40, a first expansion valve 44,a second expansion valve 48, and a first evaporator 52. The firstcondenser 32 is positioned downstream of the compressor 28. The firstcondenser 32 is coupled to an outlet port 56 of the compressor 28. Thevapor generator 36 is positioned downstream of the first condenser 32.The vapor generator 36 includes a first region 60 and a second region64. The branching point 40 is positioned between the first condenser 32and the vapor generator 36. The branching point 40 diverts a portion ofa first heat exchange fluid circulating through the refrigerant loop 24to the first region 60 of the vapor generator 36. The first expansionvalve 44 is positioned between the branching point 40 and the firstregion 60 of the vapor generator 36. An outlet 68 of the first region 60of the vapor generator 36 is coupled to a mid-pressure inlet port 72 ofthe compressor 28. The second expansion valve 48 is positioneddownstream of the vapor generator 36. The second expansion valve 48 iscoupled to an outlet 76 of the second region 64 of the vapor generator36. An inlet 80 of the second region 64 of the vapor generator 36 iscoupled to the first condenser 32. The first evaporator 52 is positioneddownstream of the second expansion valve 48. The first evaporator 52 iscoupled to the second expansion valve 48. The first evaporator 52 ispositioned upstream of the compressor 28. The first evaporator 52 iscoupled to a low-pressure inlet port 84 of the compressor 28.

Referring again to FIGS. 1-6 , the refrigerant loop 24 of the heat pump20 can include a first receiver-dryer 88 (see FIGS. 1 and 2 ) and/or anaccumulator 92 (see FIGS. 3-6 ). In examples that include the firstreceiver-dryer 88, the first receiver-dryer 88 can be positioned betweenthe first condenser 32 and the vapor generator 36. The first condenser32 can receive the first heat exchange fluid from the outlet port 56 ofthe compressor 28 at an inlet 96 of a first region 100 of the firstcondenser 32. As the first heat exchange fluid flows through the firstregion 100 of the first condenser 32, the first heat exchange fluidthermally interacts with a second heat exchange fluid (e.g., a coolant)that is flowing through a second region 104 of the first condenser 32,as indicated by arrows 106. The first heat exchange fluid exits thefirst region 100 of the first condenser 32 by way of an outlet 108 ofthe first condenser 32. Next, in examples that employ the firstreceiver-dryer 88, the first heat exchange fluid can flow into the firstreceiver-dryer 88 after exiting the first condenser 32. The firstreceiver-dryer 88 can act as a temporary storage container for the firstheat exchange fluid during low system demands when operating the heatpump 20. Additionally, the first receiver-dryer 88 can contain adesiccant that is used to absorb moisture (e.g., water) that may haveentered the first heat exchange fluid. In some examples, the firstreceiver-dryer 88 may include a filter that can trap debris that mayhave entered into the refrigerant loop 24 and/or the first heat exchangefluid. Upon exiting the first receiver-dryer 88, the first heat exchangefluid encounters the branching point 40. As the first heat exchangefluid encounters the branching point 40, a portion of the first heatexchange fluid is diverted toward the first expansion valve 44, whilethe remaining portion of the first heat exchange fluid continues towardthe vapor generator 36. In various examples, the portion of the firstheat exchange fluid that is diverted toward the first expansion valve 44can be expressed as a ratio or percentage. For example, expressing theratio as a percentage of the first heat exchange fluid that is divertedtowards the first expansion valve 44, the first expansion valve 44 canreceive about 5%, about 10%, about 15%, about 20%, about 25%, about 30%,about 35%, about 40%, about 45%, about 50%, about 55%, or about 60% ofthe first heat exchange fluid that is exiting the first receiver-dryer88. The remainder, or balancing percentage, of the first heat exchangefluid exiting the first receiver-dryer 88 that is not diverted towardthe first expansion valve 44 can continue toward the vapor generator 36.

Referring further to FIGS. 1-6 , the portion of the first heat exchangefluid that is diverted toward the first expansion valve 44 decreases inpressure and temperature as a result of interaction with the firstexpansion valve 44. After exiting the first expansion valve 44, thefirst heat exchange fluid is directed to an inlet 112 of the firstregion 60 of the vapor generator 36. As the first heat exchange fluidflows through the first region 60 of the vapor generator 36, the firstheat exchange fluid within the first region 60 thermally interacts withthe first heat exchange fluid flowing through the second region 64 ofthe vapor generator 36. As a result of the thermal interaction betweenthe first heat exchange fluid within the first region 60 and the firstheat exchange fluid within the second region 64, the first heat exchangefluid within the first region 60 exits the vapor generator 36 at theoutlet 68 of the first region 60 at a higher temperature, pressure,and/or vapor percentage. Accordingly, the portion of the refrigerantloop 24 that includes the branching point 40, the first expansion valve44, and the vapor generator 36 may be referred to as a vapor generatoror a vapor generation loop. As the first heat exchange fluid exits theoutlet 68 of the first region 60, the first heat exchange fluid isdirected toward the mid-pressure inlet port 72 of the compressor 28. Thefirst heat exchange fluid from the first region 60 of the vaporgenerator 36 is injected into the compressor 28. The injection of thefirst heat exchange fluid at the mid-pressure inlet port 72 of thecompressor 28 can improve an efficiency of the refrigerant loop 24and/or increase a heat exchange capacity of the refrigerant loop 24. Forexample, the injection of the first heat exchange fluid at themid-pressure inlet port 72 of the compressor 28 can increase acondensing capacity of the refrigerant loop 24 while decreasing a loadexperienced by the compressor 28. The improved condensing capacity ofthe refrigerant loop 24 and the decreased load on the compressor 28 cancontribute to performance and efficiency improvements for the heat pump20 and the refrigerant loop 24. Additionally, the injection of the firstheat exchange fluid at the mid-pressure inlet port 72 can increase anambient temperature operating range of the heat pump 20 and/or therefrigerant loop 24.

Referring still further to FIGS. 1-6 , the portion of the first heatexchange fluid that was not diverted toward the first expansion valve 44and instead flowed toward the inlet 80 of the second region 64 of thevapor generator 36 thermally interacts with the first heat exchangefluid that was diverted toward the first expansion valve 44. During thisthermal interaction between the first heat exchange fluid within thesecond region 64 and the first heat exchange fluid within the firstregion 60, heat is transferred from the first heat exchange fluid withinthe second region 64 to the first heat exchange fluid within the firstregion 60. Accordingly, the first heat exchange fluid exiting the vaporgenerator 36 at the outlet 76 may be at a different temperature,pressure, and/or vapor percentage than the first heat exchange fluidthat entered the inlet 80. For example, the first heat exchange fluidthat exits the vapor generator 36 at the outlet 76 of the second region64 may have a lower temperature and pressure than when the first heatexchange fluid entered the inlet 80 of the second region 64. The firstheat exchange fluid is directed toward the second expansion valve 48after exiting the second region 64 of the vapor generator 36. As withthe first expansion valve 44, the first heat exchange fluid that isdirected towards the second expansion valve 48 decreases in temperatureand pressure as a result of interaction with the second expansion valve48. As the first heat exchange fluid exits the second expansion valve48, the first heat exchange fluid is directed toward the firstevaporator 52.

Referring again to FIGS. 1-6 , as the first heat exchange fluid flowsthrough the first evaporator 52, the first heat exchange fluid thermallyinteracts with a third heat exchange fluid (e.g., a coolant) asindicated by arrows 116. In the first evaporator 52, the first heatexchange fluid absorbs thermal energy from the third heat exchange fluidsuch that the third heat exchange fluid, indicated at arrows 116,decreases in temperature and/or pressure. Accordingly, a temperature,pressure, and/or vapor percentage of the first heat exchange fluid maybe greater at an outlet 120 of the first evaporator 52 when compared toan inlet 124 of the first evaporator 52. After exiting the outlet 120 ofthe first evaporator 52, the first heat exchange fluid is directedtoward the low-pressure inlet port 84 of the compressor 28. Thecompressor 28 acts upon the first heat exchange fluid received at thelow-pressure inlet port 84 and the mid-pressure inlet port 72 toultimately direct the first heat exchange fluid out of the outlet port56 of the compressor 28 and repeat the process described above for therefrigerant loop 24.

Referring further to FIGS. 1-6 , in some examples, a second condenser128 can be positioned downstream of the compressor 28 and upstream ofthe vapor generator 36. In various examples, the second condenser 128may be plumbed in series with the first condenser 32. Alternatively, thesecond condenser 128 can be plumbed in parallel with the first condenser32. The refrigerant loop 24 of the heat pump 20 can include a firstshutoff valve 132 that is positioned upstream of the first condenser 32and downstream of the compressor 28. The first shutoff valve 132 isassociated with the first condenser 32 and is operable between an openposition and a closed position. When the first shutoff valve 132 is inthe open position, the first heat exchange fluid is allowed to passthrough the first shutoff valve 132 and into the inlet 96 of the firstregion 100 of the first condenser 32. When the first shutoff valve 132is in the closed position, the first heat exchange fluid is preventedfrom passing through the first shutoff valve 132 and thereby preventedfrom interacting with the first condenser 32. A second shutoff valve 136can be positioned upstream of the second condenser 128 when the secondcondenser 128 is employed. In such an example, the second shutoff valve136 is positioned downstream of the compressor 28.

Referring yet again to FIGS. 1-6 , the second shutoff valve 136 isassociated with the second condenser 128. The second shutoff valve 136is operable between an open position and a closed position. When thesecond shutoff valve 136 is in the open position, the first heatexchange fluid is permitted to flow through the second shutoff valve 136and into an inlet 140 of a first region 144 of the second condenser 128.The first region 144 of the second condenser 128 thermally interactswith a second region 148 of the second condenser 128. In some examples,a fourth heat exchange fluid may flow through the second region 148 ofthe second condenser 128, as indicated by arrows 152. In such examples,heat may be transferred from the first heat exchange fluid to the fourthheat exchange fluid by way of the second condenser 128. The heatacquired by the fourth heat exchange fluid may then be directed towardvarious components within the heat pump 20 that are external to therefrigerant loop 24. For example, the heat transferred to the fourthheat exchange fluid may be utilized at a heater core to provide heat toa cabin of a vehicle, to provide heat to one or more batteries of avehicle during cold weather conditions, to provide heat to windshieldwasher fluid in preparation for deicing operations, and so on. As withthe fourth heat exchange fluid, the second heat exchange fluid mayextract or absorb heat from the first heat exchange fluid by way of thefirst condenser 32. The heat acquired by the second heat exchange fluidcan be utilized in a similar manner to that discussed above with regardto the fourth heat exchange fluid. It is contemplated that, in someexamples, the second and fourth heat exchange fluids may be a singleheat exchange fluid that is split at a Y-shaped junction upstream of thefirst and second condensers 32, 128. In such an example, the second andfourth heat exchange fluids may be joined again by way of anotherY-shaped junction downstream of the first and second condensers 32, 128.In examples that employ the second condenser 128, a secondreceiver-dryer 156 may be positioned downstream of the second condenser128 and upstream of the vapor generator 36. In various modes ofoperation, the first condenser 32 and/or the second condenser 128 mayreceive the first heat exchange fluid to satisfy the demands of the heatpump 20. In examples where the second receiver-dryer 156 is omitted andthe second condenser 128 is employed, the first and second shutoffvalves 132, 136 can be employed to periodically expose the first heatexchange fluid to the first receiver-dryer 88.

With specific reference to FIGS. 3-6 , in examples that included theaccumulator 92, the accumulator 92 may be positioned between the firstevaporator 52 and the compressor 28 such that the accumulator 92 ispositioned upstream of the compressor 28 and downstream of the firstevaporator 52. In various examples, the accumulator 92 may be a suctionaccumulator. In general, the accumulator 92 can protect the compressor28 from liquid slugging or liquid being introduced into the compressor28. The accumulator 92 can also retain moisture and contaminants fromthe refrigerant loop 24 and ensure that only refrigerant, such as thefirst heat exchange fluid, is returning to the compressor 28. In someexamples, a heater 160 can be directly coupled to the accumulator 92. Insuch examples, the heater 160 can be used to provide heat to theaccumulator 92 during cold startups of the heat pump 20 (e.g., when avehicle equipped with the heat pump 20 is first started after anextended period of rest) such that a temperature, pressure, and/or vaporpercentage of the first heat exchange fluid housed within theaccumulator 92 may be increased. Heat transferred to the first heatexchange fluid by the heater 160 increases a vapor density, or vaporpercentage, at the low-pressure inlet port 84 of the compressor 28. Asthe vapor portion of the first heat exchange fluid is the sole orprimary portion of the first heat exchange fluid that is permitted toenter the compressor 28, the increased vapor percentage allows for acorresponding increase in mass flow of the first heat exchange fluidinto the compressor 28. This increased mass flow that ultimately reachesthe first condenser 32 can increase a heating capacity of the heat pump20. The compression work performed by the compressor 28 can multiply oramplify a coefficient of performance of the heat pump 20 and/or therefrigerant loop 24. In various examples of the heat pump 20 and/or therefrigerant loop 24, the coefficient of performance can be about 1.3with a heating capacity of 4 kW when the heater 160 is not employed. Insome examples, when the heater 160 is employed, the coefficient ofperformance can be about 1.5 with the heating capacity being about 4.5kW. The increase in the coefficient of performance and/or the heatingcapacity when employing the heater 160 may result from an amplificationof the input energy (e.g., electrical input energy) from the heater 160by the compression provided by the compressor 28. Said another way, theenergy provided by the heater 160 may be amplified by the compressioncycle of the compressor 28, which can in turn improve the heatingcapacity and the coefficient of performance of the heat pump 20 and/orthe refrigerant loop 24. The multiplying or amplifying effect providedby the heater 160 can enable the use of smaller electric heaters thanwould otherwise be used in conjunction with the heat pump, therebyproviding a cost-effective and high efficiency solution that improvesthe operating range of the heat pump 20 and/or the refrigerant loop 24.In some examples, the refrigerant loop 24 of the heat pump 20 may beprovided with a third expansion valve 164 that is positioned downstreamof the vapor generator 36 and upstream of the accumulator 92. In such anexample, a second evaporator 168 can be positioned downstream of thethird expansion valve 164 and upstream of the accumulator 92.

Referring again to FIGS. 3-6 , the third expansion valve 164 and thesecond evaporator 168 may be plumbed in series to the second expansionvalve 48 and the first evaporator 52. Alternatively, the third expansionvalve 164 and the second evaporator 168 may be plumbed in parallel tothe second expansion valve 48 and the first evaporator 52. Similar tothe operation of the first evaporator 52, the first heat exchange fluidcan flow through the third expansion valve 164 and into an inlet 172 ofthe second evaporator 168. Once the first heat exchange fluid hasentered the second evaporator 168 through the inlet 172, the first heatexchange fluid is flowed through a first region 174 of the secondevaporator 168 and thermally interacts with a fifth heat exchange fluid,indicated at arrows 176, which flows through a second region 178 of thesecond evaporator 168. Heat from the fifth heat exchange fluid can betransferred to the first heat exchange fluid by way of the secondevaporator 168. Accordingly, the fifth heat exchange fluid may be cooledas a result of interaction with the second evaporator 168. The cooledfifth heat exchange fluid can be directed toward components of the heatpump 20 that are external to the refrigerant loop 24 and may benefitfrom heat extraction. For example, the fifth heat exchange fluid may bedirected to heat-producing components of the heat pump 20, such asbatteries of a vehicle, an engine of a vehicle, electronic components ofa vehicle, and/or may be utilized in providing cooled air to a cabin ofa vehicle that is equipped with the heat pump 20. Similarly, the thirdheat exchange fluid, indicated at arrows 116, that flows through thefirst evaporator 52 can reject heat from the third heat exchange fluidto the first heat exchange fluid by way of interaction with the firstevaporator 52. The cooled third heat exchange fluid may be utilized in asimilar manner to that discussed above with regard to the fifth heatexchange fluid.

Referring further to FIGS. 3-6 , in various examples, the secondexpansion valve 48 and/or the third expansion valve 164 may be capableof operating as a shutoff valve. Accordingly, in examples that employthe second expansion valve 48 and the third expansion valve 164, thefirst and second evaporators 52, 168 may be employed selectivelydepending on the demands of the heat pump 20. As with the first andsecond condensers 32, 128 discussed above, the third heat exchange fluidand the fifth heat exchange fluid, which flow through the firstevaporator 52 and the second evaporator 168, respectively, may be partof the same loop that is external to the refrigerant loop 24 or may bepart of separate loops that are external from the refrigerant loop 24.In examples where the first and second evaporators 52, 168 are coupledto the same loop that is external to the refrigerant loop 24, the thirdand fifth heat exchange fluids may be the same heat exchange fluid,which is flowed through a Y-shaped junction that is upstream of thefirst and second evaporators 52, 168. In such an example, anotherY-shaped junction may be provided downstream of the first and secondevaporators 52, 168 such that the third and fifth heat exchange fluidsare recombined for circulation in the loop that is external to therefrigerant loop 24.

The various architectures depicted in FIGS. 1-6 with regard to therefrigerant loop 24 are intended to be exemplary in nature and notlimiting. For example, the first condenser 32 and/or the secondcondenser 128 may be employed in an architecture of the refrigerant loop24 with the first evaporator 52 and/or the second evaporator 168 withoutdeparting from the concepts disclosed herein. Similarly, it iscontemplated that a third condenser and/or a third evaporator may beemployed to fit particular needs or demands of a given heat pump 20. Thevarious architectures depicted for the refrigerant loop 24 with regardto the use of the first receiver-dryer 88, the second receiver-dryer156, the accumulator 92, the first condenser 32, the second condenser128, the first evaporator 52, and/or the second evaporator 168 areintended to depict examples of how the refrigerant loop 24 may beexpanded to accommodate a variety of arrangements of the heat pump 20.Accordingly, the concepts disclosed herein can be employed to assemblean architecture for the refrigerant loop 24 that is not explicitlyshown, but would fall within the concepts disclosed herein.

Referring now to FIGS. 7-11 , the refrigerant loop 24 discussed withregard to FIGS. 1-6 are expanded upon to show additional architecturesthat are contemplated by the present disclosure. As discussed above, theheat pump 20 includes the refrigerant loop 24. The refrigerant loop 24includes the compressor 28, the first condenser 32, the vapor generator36, the branching point 40, the first expansion valve 44, the secondexpansion valve 48, and the first evaporator 52. In the depictedexamples, the branching point 40 may be referred to as a first branchingpoint 180. The first condenser 32 is positioned downstream of thecompressor 28. The first condenser 32 is coupled to the outlet port 56of the compressor 28. The vapor generator 36 is positioned downstream ofthe first condenser 32. The vapor generator 36 includes the first region60 and the second region 64. The first branching point 180 is positionedbetween the first condenser 32 and the vapor generator 36. The firstbranching point 180 diverts a portion of the first heat exchange fluidthat is circulating through the refrigerant loop 24 to the first region60 of the vapor generator 36. The first expansion valve 44 is positionedbetween the first branching point 180 in the first region 60 of thevapor generator 36. The outlet 68 of the first region 60 of the vaporgenerator 36 is coupled to the mid-pressure inlet port 72 of thecompressor 28. The second expansion valve 48 is positioned downstream ofthe vapor generator 36. The second expansion valve 48 is coupled to theoutlet 76 of the second region 64 of the vapor generator 36. The inlet80 of the second region 64 of the vapor generator 36 is coupled to thefirst condenser 32. The first evaporator 52 is positioned downstream ofthe second expansion valve 48. The first evaporator 52 is coupled to thesecond expansion valve 48. The first evaporator 52 is positionedupstream of the compressor 28. The first evaporator is coupled to thelow-pressure inlet port 84 of the compressor 28.

Referring again to FIGS. 7-11 , the depicted architectures of therefrigerant loop 24 are shown with the first receiver-dryer 88. However,these architectures are not limited to the sole use of the firstreceiver-dryer 88 to the exclusion of the incorporation of theaccumulator 92. Rather, for the sake of brevity, the additionalarchitectures that would employ the accumulator 92 are omitted as sucharrangements have been discussed with regard to FIGS. 1-6 and suchteachings can be employed in arriving at architectures that employ theaccumulator 92. By way of example, the accumulator 92, when employed,can be positioned immediately upstream of the compressor 28 such thatthe low-pressure inlet port 84 of the compressor 28 receives the firstheat exchange fluid directly from the accumulator 92. As with theabove-described architectures, the first condenser 32 can receive thefirst heat exchange fluid from the outlet port 56 of the compressor 28at the inlet 96 of the first region 100 of the first condenser 32. Asthe first heat exchange fluid flows through the first region 100 of thefirst condenser 32, the first heat exchange fluid thermally interactswith the second heat exchange fluid that is flowing through the secondregion 104 of the first condenser 32, as indicated by the arrows 106.The first heat exchange fluid exits the first region 100 of the firstcondenser 32 by way of the outlet 108 of the first condenser 32. Next,the first heat exchange fluid can flow into the first receiver-dryer 88after exiting the first condenser 32.

Referring further to FIGS. 7-11 , as stated above, the firstreceiver-dryer 88 can act as a temporary storage container for the firstheat exchange fluid during low system demands when operating the heatpump 20. Additionally, the first receiver-dryer 88 can contain adesiccant that is used to absorb moisture (e.g., water) that may haveentered the first heat exchange fluid. In some examples, the firstreceiver-dryer 88 may include a filter that can trap debris that mayhave entered into the refrigerant loop 24 and/or the first heat exchangefluid. Upon exiting the first receiver-dryer 88, the first heat exchangefluid encounters the first branching point 180. As the first heatexchange fluid encounters the first branching point 180, a portion ofthe first heat exchange fluid is diverted toward of the first expansionvalve 44, while the remaining portion of the first heat exchange fluidcontinues toward the vapor generator 36. In various examples, theportion of the first heat exchange fluid that is diverted toward thefirst expansion valve 44 can be expressed as a ratio or percentage. Forexample, expressing the ratio as a percentage of the first heat exchangefluid that is diverted toward the first expansion valve 44, the firstexpansion valve 44 can receive about 5%, about 10%, about 15%, about20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%,about 55%, or about 60% of the first heat exchange fluid that is exitingthe first receiver-dryer 88. The remainder, or balance in percentage, ofthe first heat exchange fluid exiting the first receiver-dryer 88 thatis not diverted toward the first expansion valve 44 can continue towardof the vapor generator 36. The portion of the first heat exchange fluidthat is diverted toward the first expansion valve 44 decreases inpressure and temperature as a result of interaction with the firstexpansion valve 44. After exiting the first expansion valve 44, thefirst heat exchange fluid is directed to the inlet 112 of the firstregion 60 of the vapor generator 36. As the first heat exchange fluidflows through the first region 60 of the vapor generator 36, the firstheat exchange fluid within the first region 60 thermally interacts withthe first heat exchange fluid flowing through the second region 64 ofthe vapor generator 36. As a result of the thermal interaction betweenthe first heat exchange fluid within the first region 60 and the firstheat exchange fluid within the second region 64, the first heat exchangefluid within the first region 60 exits the vapor generator 36 at theoutlet 68 of the first region 60 at a higher temperature, pressure,and/or vapor percentage. Accordingly, the portion of the refrigerantloop 24 that includes the first branching point 180, the first expansionvalve 44, and the vapor generator 36 may be referred to as a vaporgenerator or a vapor generation loop.

Referring still further to FIGS. 7-11 , as the first heat exchange fluidexits the outlet 68 of the first region 60, the first heat exchangefluid is directed toward the mid-pressure inlet port 72 of thecompressor 28. The first heat exchange fluid from the first region 60 ofthe vapor generator 36 is injected into the compressor 28. The injectionof the first heat exchange fluid at the mid-pressure inlet port 72 ofthe compressor 28 can improve the efficiency of the refrigerant loop 24and/or increase heat exchange capacity of the refrigerant loop 24. Forexample, the injection of the first heat exchange fluid at themid-pressure inlet port 72 of the compressor 28 can increase acondensing capacity of the refrigerant loop 24 while decreasing a loadexperienced by the compressor 28. The improved condensing capacity ofthe refrigerant loop 24 and the decreased load on the compressor 28 cancontribute to performance and efficiency improvements for the heat pump20 and the refrigerant loop 24. Additionally, the injection of the firstheat exchange fluid at the mid-pressure inlet port 72 can increase theambient temperature operating range of the heat pump 20 and/or therefrigerant loop 24. The portion of the first heat exchange fluid thatwas not diverted toward the first expansion valve 44 and instead flowedtoward the inlet 80 of the second region 64 of the vapor generator 36interacts with the first heat exchange fluid that was diverted towardthe first expansion valve 44. During this thermal interaction betweenthe first heat exchange fluid within the second region 64 and the firstheat exchange fluid within the first region 60, heat is transferred fromthe first heat exchange fluid within the second region 64 to the firstheat exchange fluid within the first region 60. Accordingly, the firstheat exchange fluid exiting the vapor generator 36 at the outlet 76 maybe at a different temperature, pressure, and/or vapor percentage thanthe first heat exchange fluid that entered the inlet 80. For example,the first heat exchange fluid that exits the vapor generator 36 at theoutlet 76 of the second region 64 may have a lower temperature andpressure when compared to the first heat exchange fluid that entered theinlet 80.

Referring yet again to FIGS. 7-11 , the first heat exchange fluid isdirected toward the second expansion valve 48 after exiting the secondregion 64 of the vapor generator 36. As with the first expansion valve44, the first heat exchange fluid that is directed towards the secondexpansion valve 48 decreases in temperature and pressure as a result ofinteraction with the second expansion valve 48. As the first heatexchange fluid exits the second expansion valve 48, the first heatexchange fluid is directed toward the first evaporator 52. As the firstheat exchange fluid flows through the first evaporator 52, the firstheat exchange fluid thermally interacts with the third heat exchangefluid (e.g., a coolant) as indicated by the arrows 116. In the firstevaporator 52, the first heat exchange fluid absorbs thermal energy fromthe third heat exchange fluid such that the third heat exchange fluid,indicated at the arrows 116, decreases in temperature and/or pressure.Accordingly, a temperature, pressure, and/or vapor percentage of thefirst heat exchange fluid may be greater at the outlet 120 of the firstevaporator 52 when compared to the inlet 124 of the first evaporator 52.After exiting the outlet 120 of the first evaporator 52, the first heatexchange fluid is directed toward the low-pressure inlet port 84 of thecompressor 28. The compressor 28 acts upon the first heat exchange fluidreceived at the low-pressure inlet port 84 and the mid-pressure inletport 72 to ultimately direct the first heat exchange fluid out of theoutlet port 56 of the compressor 28 and repeat the process describedabove for the refrigerant loop 24.

Referring again to FIGS. 7-11 , the refrigerant loop 24 of the heat pump20 may be provided with the second evaporator 168 positioned downstreamof the vapor generator 36 and coupled to the outlet 76 of the secondregion 64 of the vapor generator 36. In such an example, the thirdexpansion valve 164 can be positioned between the second evaporator 168and the vapor generator 36. Additionally, in such examples, the secondevaporator 168 is positioned upstream of the compressor 28 and iscoupled to the low-pressure inlet port 84 of the compressor 28. In someexamples, the second evaporator 168 and the third expansion valve 164can be plumbed in series with the first evaporator 52 and the secondexpansion valve 48. Alternatively, the second evaporator 168 and thethird expansion valve 164 can be plumbed in parallel to the firstevaporator 52 and the second expansion valve 48. Similar to theoperation of the first evaporator 52, the first heat exchange fluid canflow through the third expansion valve 164 and into the inlet 172 of thesecond evaporator 168. Once the first heat exchange fluid has enteredthe second evaporator 168 through the inlet 172, the first heat exchangefluid flows through the first region 174 of the second evaporator 168and thermally interacts with the first heat exchange fluid, indicated bythe arrows 176, which flows through the second region 178 of the secondevaporator 168.

Referring further to FIGS. 7-11 , heat from the fifth heat exchangefluid can be transferred to the first heat exchange fluid by way of thesecond evaporator 168. Accordingly, the fifth heat exchange fluid may becooled as a result of interaction with the second evaporator 168. Thecooled fifth heat exchange fluid can be directed toward components ofthe heat pump 20 that are external to the refrigerant loop 24 and maybenefit from heat extraction. For example, the fifth heat exchange fluidmay be directed to heat-producing components of the heat pump 20, suchas batteries of a vehicle, an engine of a vehicle, electronic componentsof the vehicle, and/or may be utilized in providing cooled air to acabin of a vehicle that is equipped with the heat pump 20. Similarly,the third heat exchange fluid, indicated at the arrows 116, that flowsthrough the first evaporator 52 can reject heat from the third heatexchange fluid to the first heat exchange fluid by way of interactionwith the first evaporator 52. The cooled third heat exchange fluid maybe utilized in a similar manner to that discussed above with regard tothe fifth heat exchange fluid. In various examples, the second expansionvalve 48 and/or the third expansion valve 164 may be capable ofoperating as a shut off valve. Accordingly, in examples that employ thesecond expansion valve 48 and the third expansion valve 164, the firstand second evaporator 52, 168 may be employed selectively depending onthe demand of the heat pump 20. As with the first and second condensers32, 128 discussed above, the third heat exchange fluid and the fifthheat exchange fluid, which flow through the first evaporator 52 and thesecond evaporator 168, respectively, may be part of the same loop thatis external to the refrigerant loop 24 or may be part of different loopsthat are external from the refrigerant loop 24. In examples where thefirst and second evaporators 52, 168 are coupled to the same loop thatis external to the refrigerant loop 24, the third and fifth heatexchange fluids may be the same heat exchange fluid, which is flowedthrough a Y-shaped junction that is upstream of the first and secondevaporators 52, 168. In such an example, another Y-shaped junction maybe provided downstream of the first and second evaporators 52, 168 suchthat the third and fifth heat exchange fluids are combined forcirculation in the loop that is external to the refrigerant loop 24. Inexamples where the third expansion valve 164 and the second evaporator168 are plumbed in parallel to the second expansion valve 48 and thefirst evaporator 52, a second branching point 184 can be positioneddownstream of the outlet 76 of the second region 64 of the vaporgenerator 36 and upstream of the second and third expansion valves 48,164. Additionally, in such examples, a first convergence point 188 maybe positioned upstream of the compressor 28 and downstream of the firstand second evaporators 52, 168.

Referring still further to FIGS. 7-11 , the vapor generator 36 caninclude a third region 192. The third region 192 is positioneddownstream of the first evaporator 52 and upstream of the compressor 28.An outlet 196 of the third region 192 is coupled to the low-pressureinlet port 84 of the compressor 28. For example, the outlet 196 of thethird region 192 can be directly coupled to the low-pressure inlet port84 of the compressor 28. In such examples, the first, second, and thirdregions 60, 64, 192 of the vapor generator 36 thermally interact withone another such that heat is transferred between the first heatexchange fluid in each of the sections of the vapor generator. Morespecifically, the first heat exchange fluid flowing through the firstregion 60 absorbs heat from the first heat exchange fluid that isflowing through the second region 64. This arrangement is beneficial forthe next stage of the refrigerant loop 24 that each of these portions ofthe first heat exchange fluid will be advancing to once exiting thevapor generator 36. For example, the first heat exchange fluid in thefirst region 60 absorbs some of the heat from the first heat exchangefluid within the second region 64 such that a temperature, pressure,and/or vapor percentage of the first heat exchange fluid is increased atthe outlet 68 of the first region 60. This increase in the temperature,the pressure, and/or the vapor percentage of the first heat exchangefluid that is entering into the mid-pressure inlet port 72 of thecompressor 28 can improve an efficiency or capacity of the refrigerantloop 24 and/or the compressor 28, as discussed above. In a related, andinverse, manner the first heat exchange fluid flowing through the secondregion 64 exhibits a decreased temperature, pressure, and/or vaporpercentage at the outlet 76 of the second region 64. Once leaving theoutlet 76 of the second region 64, the first heat exchange fluid flowsto the second expansion valve 48 and/or the third expansion valve 164,as well as the first evaporator 52 and/or the second evaporator 168. Atthe first evaporator 52 and/or the second evaporator 168, the first heatexchange fluid can cool the third heat exchange fluid and/or the fifthheat exchange fluid by absorbing heat from these other heat exchangefluids. Accordingly, the first heat exchange fluid may be provided witha degree of pre-cooling by the interaction between the first and secondregions 60, 64 within the vapor generator 36. This pre-cooling of thefirst heat exchange fluid can improve a coefficient of performance ofthe heat pump 20 and/or the refrigerant loop 24. For example, bypre-cooling the first heat exchange fluid prior to interaction with thesecond expansion valve 48 and the first evaporator 52 and/or interactionwith the third expansion valve 164 and the second evaporator 168, agreater amount of heat or thermal energy may be extracted from the thirdheat exchange fluid and/or the fifth heat exchange fluid.

Referring yet again to FIGS. 7-11 , the third region 192 can thermallyinteract with the second region 64 in a similar manner to that describedabove with regard to the first region 60. Accordingly, as with the firstregion 60, the third region 192 may extract a degree of heat from thefirst heat exchange fluid flowing through the second region 64 such thata temperature, pressure, and/or vapor percentage of the first heatexchange fluid flowing through the third region 192 may be increased. Aswith the thermal exchange discussed with regard to the first region 60,by increasing the temperature, pressure, and/or vapor percentage of thefirst heat exchange fluid that is exiting the third region 192, theefficiency and/or capacity of the heat pump 20 and/or the compressor 28may be similarly increased. Additionally, the first heat exchange fluidflowing through the second region 64 may be further pre-cooled andprovided with an increase in the benefits discussed above with regard tothe pre-cooling provided by the first region 60. In various examples,the pre-cooling provided by the first region 60 may be referred to as afirst pre-cooling of the first heat exchange fluid flowing through thesecond region 64 and the pre-cooling provided by the third region 192may be referred to as a second pre-cooling of the first heat exchangefluid flowing through the second region 64. In the example of the vaporgenerator 36 described above as including the third region 192, thefirst, second, and third regions 60, 64, 192 are plumbed in parallel toone another and may be housed within a single body of the vaporgenerator 36. It may be beneficial to plumb the portion of the vaporgenerator 36 that experiences cooling (e.g., the second region 64)between the portions of the vapor generator 36 that experience heating(e.g., the first and third regions 60, 192) so that heat may besimultaneously extracted.

Referring still further to FIGS. 7-11 , in some examples, the thirdregion 192 of the vapor generator 36 may be omitted and a heat exchanger200 may be plumbed in series with the vapor generator 36 instead. Theheat exchanger 200, when employed, includes a first region 204 and asecond region 208. The first region 204 of the heat exchanger 200 isplumbed in series with the second region 64 of the vapor generator 36such that an inlet 212 of the first region 204 of the heat exchanger 200is directly coupled to the outlet 76 of the second region 64 of thevapor generator 36. The second region 208 of the heat exchanger 200 ispositioned downstream of the first evaporator 52 and upstream of thecompressor 28. An outlet 216 of the second region 208 of the heatexchanger 200 is coupled to the low-pressure inlet port 84 of thecompressor 28. The benefits of the heat exchanger 200 are the same asthat described above with regard to the third region 192. Morespecifically, the heat exchanger 200 may extract a degree of heat fromthe first heat exchange fluid flowing through the first region 204thereof such that a temperature, pressure, and/or vapor percentage ofthe first heat exchange fluid flowing through the second region 208 maybe increased. Increasing the temperature, pressure, and/or vaporpercentage of the first heat exchange fluid that is exiting the secondregion 208 can increase the efficiency and/or capacity of the heat pump20 and/or the compressor 28. Additionally, the first heat exchange fluidflowing through the first region 204 may be further pre-cooled andprovided with an increase in the benefits discussed above with regard tothe pre-cooling provided by the vapor generator 36. In various examples,the pre-cooling provided by the vapor generator 36 may be referred to asa first pre-cooling of the first heat exchange fluid flowing through thesecond region 64 and the pre-cooling provided by the heat exchanger 200may be referred to as a second pre-cooling of the first heat exchangefluid flowing through the first region 204.

Referring yet again to FIGS. 7-11 , the refrigerant loop 24 of the heatpump 20 can include a bypass loop 220. The bypass loop 220 includes ashutoff valve 224 that is operable between an open position and a closedposition. When the shutoff valve 224 is in the open position, a sectionof the refrigerant loop is bypassed. More specifically, in examples thatemploy the third region 192, the open position of the shutoff valve 224bypasses the third region 192 of the vapor generator 36. Similarly, inexamples that employ the heat exchanger 200, the open position of theshutoff valve 224 can bypass the second region 208 of the heat exchanger200. Accordingly, the bypass loop 220 couples to the refrigerant loop 24at a third branching point 228. The third branching point 228 ispositioned upstream of the third region 192 of the vapor generator 36.The third branching point 228 can be positioned downstream of the firstevaporator 52 and/or the second evaporator 168. The third branchingpoint 228 may alternatively be referred to as an inlet of the bypassloop 220. In various examples, the third region 192 may providesufficient back pressure or resistance to flow that the first heatexchange fluid does not enter into an inlet 232 of the third region 192when the shutoff valve 224 is in the open position. Accordingly, amajority or an entirety of the first heat exchange fluid encounteringthe third branching point 228 may be diverted to the bypass loop 220once the shutoff valve 224 is in the open position. The bypass loop 220may rejoin the refrigerant loop 24 at a second convergence point 236that is positioned downstream of the outlet 196 of the third region 192of the vapor generator 36 and upstream of the low-pressure inlet port 84of the compressor 28. Bypassing the third region 192 of the vaporgenerator or the second region 208 of the heat exchanger 200 can, forexample, avoid the second pre-cooling of the first heat exchange fluidduring heating modes of operation, where the additional pre-cooling maynegatively impact performance of the heat pump 20 and/or the refrigerantloop 24.

Referring again to FIGS. 7-11 , in some examples, the bypass loop 220can include a bypass heat exchanger 240 that is positioned downstream ofthe shutoff valve 224. In various examples, a bypass heater 244 may bedirectly coupled to the bypass heat exchanger 240 such that the bypassheater 244 provides thermal energy to the first heat exchange fluid whenthe first heat exchange fluid is passed through the bypass heatexchanger 240. In such examples, the bypass heater 244 can operate in asimilar manner to the heater 160 that was discussed as being directlycoupled to the accumulator 92 with regard to FIGS. 3-6 . For example,the bypass heater 244 can be used to provide heat to the first heatexchange fluid during cold startups of the heat pump 20 (e.g., when avehicle equipped with the heat pump 20 is first started after anextended period of rest) such that a temperature, pressure, and/or vaporpercentage of the first heat exchange fluid that is passing through thebypass heat exchanger 240 may be increased. Such a mode of operation canbe beneficial when heat-producing components of the heat pump 20 havenot been operating for a long enough period of time to result in adesired amount of heat exchange within the refrigerant loop 24 and/orthroughout the heat pump 20. As with the heater 160, heat transferred tothe first heat exchange fluid by the bypass heater 244 increases a vapordensity, or vapor percentage, at the low-pressure inlet port 84 of thecompressor 28. As the vapor portion of the first heat exchange fluid isthe sole or primary portion of the first heat exchange fluid that ispermitted to enter the compressor 28, the increased vapor percentageallows for a corresponding increase in mass flow of the first heatexchange fluid into the compressor 28. This increased mass flow thatultimately reaches the first condenser 32 can increase a heatingcapacity of the heat pump 20. The compression work performed by thecompressor 28 can multiply or amplify a coefficient of performance ofthe heat pump 20 and/or the refrigerant loop 24. In various examples ofthe heat pump 20 and/or the refrigerant loop 24, the coefficient ofperformance can be about 1.3 with a heating capacity of 4 kW when theheater 160 is not employed. In some examples, when the heater 160 isemployed, the coefficient of performance can be about 1.5 with theheating capacity being about 4.5 kW. The increase in the coefficient ofperformance and/or the heating capacity when employing the heater 160may result from an amplification of the input energy (e.g., electricalinput energy) from the heater 160 by the compression provided by thecompressor 28. Said another way, the energy provided by the heater 160may be amplified by the compression cycle of the compressor 28, whichcan in turn improve the heating capacity and the coefficient ofperformance of the heat pump 20 and/or the refrigerant loop 24. Themultiplying or amplifying effect provided by the bypass heater 244 canenable the use of smaller electric heaters than would otherwise be usedin conjunction with the heat pump, thereby providing a cost-effectiveand high efficiency solution that improves the operating range of theheat pump 20 and/or the refrigerant loop 24.

With particular reference to FIG. 11 , the heat pump 20 may be providedwith an auxiliary refrigerant loop 248. The auxiliary refrigerant loop248 can include an auxiliary compressor 252. The auxiliary compressor252, similar to the compressor 28, includes an outlet port 256, amid-pressure inlet port 260, and a low-pressure inlet port 264. Anauxiliary condenser 268 is positioned downstream of the auxiliarycompressor 252 and coupled to the outlet port 256 of the auxiliarycompressor 252. An auxiliary vapor generator 272 is positioneddownstream of the auxiliary condenser 268. A first region 276 of theauxiliary vapor generator 272 is coupled to the auxiliary condenser 268.More specifically, an inlet 280 of the first region 276 is coupled to anoutlet 284 of a first region 288 of the auxiliary condenser. A firstauxiliary expansion valve 292 is positioned downstream of the auxiliaryvapor generator 272 and is coupled to the auxiliary vapor generator 272at an outlet 296 of the first region 276 of the auxiliary vaporgenerator 272. An auxiliary evaporator 300 is positioned downstream ofthe first auxiliary expansion valve 292. The auxiliary evaporator 300 isupstream of the auxiliary compressor 252 and is coupled to thelow-pressure inlet port 264 of the auxiliary compressor 252. Anauxiliary branching point 304 is positioned between the auxiliarycondenser 268 and the auxiliary vapor generator 272. The auxiliarybranching point 304 diverts a portion of the auxiliary heat exchangefluid circulating through the auxiliary refrigerant loop 248 to a secondregion 308 of the auxiliary vapor generator 272. An outlet 312 of thesecond region 308 of the auxiliary vapor generator 272 is coupled to themid-pressure inlet port 260 of the auxiliary compressor 252.

Referring again to FIG. 11 , a second auxiliary expansion valve 316 ispositioned between the auxiliary branching point 304 and an inlet 320 ofthe second region 308 of the auxiliary vapor generator 272. In someexamples, the auxiliary refrigerant loop 248 can include an auxiliaryreceiver-dryer 324 that is positioned downstream of the auxiliarycondenser 268. In various examples, the auxiliary condenser 268 and thefirst condenser 32 can each receive the second heat exchange fluid thatis circulated through a first external loop. For example, the auxiliarycondenser 268 and the first condenser 32 can be plumbed in series alongthe first external loop such that the refrigerant loop 24 and theauxiliary refrigerant loop 248 each thermally interact with the sameheat exchange fluid and amplify the heat exchange capabilities of oneanother. Alternatively, the auxiliary condenser 268 and the firstcondenser 32 may be plumbed in parallel and serve separate componentsand/or separate external loops. Similarly, in some examples, the firstevaporator 52 and the auxiliary evaporator 300 can each receive thethird heat exchange fluid, as indicated by the arrows 116, with thethird heat exchange fluid being circulated through a second externalloop. For example, the first evaporator 52 and the auxiliary evaporator300 can be plumbed in series along the second external loop such thatthe refrigerant loop 24 and the auxiliary refrigerant loop 248collectively act upon the third heat exchange fluid. Accordingly, therefrigerant loop 24 and the auxiliary refrigerant loop 248 may amplify aheat exchange capacity and/or a heat exchange efficiency of the heatpump 20. Alternatively, the first evaporator 52 and the auxiliaryevaporator 300 may be plumbed in parallel and serve separate componentsand/or separate external loops.

FIG. 11 is an exemplary depiction of combining two of the arrangementsof the heat pump 20 disclosed herein in a manner that can be utilizedfor a particular set of demands for a given one of the heat pumps 20.Therefore, FIG. 11 represents a non-limiting example of how one maycombine the various heat pump 20 and/or refrigerant loop 24 arrangementsdisclosed herein to obtain a desired heat exchange capacity and/or heatexchange efficiency. It is contemplated that two or more of therefrigerant loops 24 disclosed herein may be employed in a given exampleof the heat pump 20 without departing from the concepts disclosedherein. In a similar manner, the present disclosure provides a varietyof modifications to the refrigerant loop 24 that can be employed in aneffort to fine-tune the heat exchange capacity and/or the heat exchangeefficiency provided to the heat pump 20 and/or the refrigerant loop 24(e.g., adjusting the number of condensers, the number of evaporators,the number of expansion valves, and so on) without departing from theconcepts disclosed herein. Regardless of the architecture of therefrigerant loop 24 and/or the number of refrigerant loops 24 employedin a given heat pump 20, the heat exchange fluids that are external tothe refrigerant loop(s) 24 (e.g., the second heat exchange fluid, thethird heat exchange fluid, the fourth heat exchange fluid, and/or thefifth heat exchange fluid) may circulate through independent heatexchange loops (e.g., coolant loops) that do not thermally interact in adirect manner (e.g., no coolant-to-coolant heat exchange).Alternatively, one or more of the heat exchange fluids that are externalto the refrigerant loop(s) 24 may circulate through a common heatexchange loop that is external to the refrigerant loop(s) 24, such asthe example(s) described above with regard to Y-shaped junctionsupstream and/or downstream of various components of the refrigerant loop24. However, the present disclosure is not limited by any particulararchitecture of heat exchange loops that are external to the refrigerantloop 24 (e.g., coolant loops).

Modifications of the disclosure will occur to those skilled in the artand to those who make or use the concepts disclosed herein. Therefore,it is understood that the embodiments shown in the drawings anddescribed above are merely for illustrative purposes and not intended tolimit the scope of the disclosure, which is defined by the followingclaims as interpreted according to the principles of patent law,including the doctrine of equivalents.

It will be understood by one having ordinary skill in the art thatconstruction of the described concepts, and other components, is notlimited to any specific material. Other exemplary embodiments of theconcepts disclosed herein may be formed from a wide variety ofmaterials, unless described otherwise herein.

For purposes of this disclosure, the term “coupled” (in all of itsforms: couple, coupling, coupled, etc.) generally means the joining oftwo components (electrical or mechanical) directly or indirectly to oneanother. Such joining may be stationary in nature or movable in nature.Such joining may be achieved with the two components (electrical ormechanical) and any additional intermediate members being integrallyformed as a single unitary body with one another or with the twocomponents. Such joining may be permanent in nature, or may be removableor releasable in nature, unless otherwise stated.

It is also important to note that the construction and arrangement ofthe elements of the disclosure, as shown in the exemplary embodiments,is illustrative only. Although only a few embodiments of the presentinnovations have been described in detail in this disclosure, thoseskilled in the art who review this disclosure will readily appreciatethat many modifications are possible (e.g., variations in sizes,dimensions, structures, shapes and proportions of the various elements,values of parameters, mounting arrangements, use of materials, colors,orientations, etc.) without materially departing from the novelteachings and advantages of the subject matter recited. For example,elements shown as integrally formed may be constructed of multipleparts, or elements shown as multiple parts may be integrally formed, theoperation of the interfaces may be reversed or otherwise varied, thelength or width of the structures and/or members or connector or otherelements of the system may be varied, and the nature or numeral ofadjustment positions provided between the elements may be varied. Itshould be noted that the elements and/or assemblies of the system may beconstructed from any of a wide variety of materials that providesufficient strength or durability, in any of a wide variety of colors,textures, and combinations. Accordingly, all such modifications areintended to be included within the scope of the present innovations.Other substitutions, modifications, changes, and omissions may be madein the design, operating conditions, and arrangement of the desired andother exemplary embodiments without departing from the spirit of thepresent innovations.

It will be understood that any described processes, or steps withindescribed processes, may be combined with other disclosed processes orsteps to form structures within the scope of the present disclosure. Theexemplary structures and processes disclosed herein are for illustrativepurposes and are not to be construed as limiting.

It is also to be understood that variations and modifications can bemade on the aforementioned structures and methods without departing fromthe concepts of the present disclosure, and further, it is to beunderstood that such concepts are intended to be covered by thefollowing claims, unless these claims, by their language, expresslystate otherwise.

What is claimed is:
 1. A heat pump, comprising: a refrigerant loop,wherein the refrigerant loop comprises: a compressor; a first condenserdownstream of the compressor and coupled to an outlet port of thecompressor; a vapor generator downstream of the first condenser, whereinthe vapor generator comprises a first region having a first inlet and afirst outlet and a second region having a second inlet and a secondoutlet, and wherein the vapor generator receives a first heat exchangefluid; a first receiver-dryer positioned between the first condenser andthe vapor generator; a first branching point positioned between thefirst condenser and the vapor generator, wherein the first branchingpoint diverts a portion of the first heat exchange fluid circulatingthrough the refrigerant loop to the first inlet of the vapor generator;a first expansion valve positioned between the first branching point andthe first inlet of the vapor generator, wherein the first outlet of thevapor generator is coupled to a mid-pressure inlet port of thecompressor; a first evaporator downstream of the vapor generator andcoupled to the second outlet of the vapor generator; a second expansionvalve positioned between the first evaporator and the vapor generator,wherein the first evaporator is upstream of the compressor and iscoupled to a low-pressure inlet port of the compressor; and a heatexchanger having a first region and a second region, wherein the firstregion of the heat exchanger is positioned between the second outlet ofthe vapor generator and the second expansion valve, wherein the firstregion of the heat exchanger is plumbed in series with the second regionof the vapor generator such that an inlet of the first region of theheat exchanger is directly coupled to an outlet of the second region ofthe vapor generator.
 2. The heat pump of claim 1, wherein an inlet ofthe second region of the heat exchanger is positioned downstream of thefirst evaporator.
 3. The heat pump of claim 1, wherein an outlet of thesecond region of the heat exchanger is positioned upstream of thelow-pressure inlet port of the compressor.
 4. The heat pump of claim 1,further comprising: a second evaporator downstream of the vaporgenerator and coupled to the second outlet of the vapor generator. 5.The heat pump of claim 4, wherein the second evaporator is plumbed inparallel to the first evaporator.
 6. The heat pump of claim 4, furthercomprising: a third expansion valve positioned between the secondevaporator and the vapor generator.
 7. The heat pump of claim 6, whereinthe third expansion valve is plumbed in parallel with the secondexpansion valve.
 8. The heat pump of claim 4, wherein an inlet of thesecond region of the heat exchanger is positioned downstream of thesecond evaporator.
 9. The heat pump of claim 1, further comprising: abypass loop having an inlet and an outlet, wherein the bypass loop isconfigured to bypass the second region of the heat exchanger.
 10. Theheat pump of claim 9, wherein the inlet of the bypass loop is positionedimmediately upstream of the second region of the heat exchanger.
 11. Theheat pump of claim 9, wherein the outlet of the bypass loop ispositioned immediately upstream of the low-pressure inlet port of thecompressor.
 12. The heat pump of claim 9, wherein the bypass loopcomprises a shutoff valve positioned between the inlet of the bypassloop and the outlet of the bypass loop.
 13. The heat pump of claim 1,further comprising: an auxiliary refrigerant loop, wherein the auxiliaryrefrigerant loop comprises: an auxiliary compressor; an auxiliarycondenser downstream of the auxiliary compressor and coupled to anoutlet port of the auxiliary compressor; an auxiliary expansion valvedownstream of the auxiliary condenser; and an auxiliary evaporatordownstream of the auxiliary expansion valve and coupled to the auxiliaryexpansion valve, wherein the auxiliary evaporator is upstream of theauxiliary compressor and is coupled to a low-pressure inlet port of theauxiliary compressor.
 14. The heat pump of claim 13, further comprising:an auxiliary receiver-dryer positioned downstream of the auxiliarycondenser, wherein the auxiliary receiver-dryer is positioned upstreamof the auxiliary evaporator.
 15. A heat pump, comprising: a refrigerantloop, wherein the refrigerant loop comprises: a compressor; a firstcondenser downstream of the compressor and coupled to an outlet port ofthe compressor; a vapor generator downstream of the first condenser,wherein the vapor generator comprises a first region having a firstinlet and a first outlet and a second region having a second inlet and asecond outlet, and wherein the vapor generator receives a first heatexchange fluid; a first receiver-dryer positioned between the firstcondenser and the vapor generator; a first branching point positionedbetween the first condenser and the vapor generator, wherein the firstbranching point diverts a portion of the first heat exchange fluidcirculating through the refrigerant loop to the first inlet of the vaporgenerator; a first expansion valve positioned between the firstbranching point and the first inlet of the vapor generator, wherein thefirst outlet of the vapor generator is coupled to a mid-pressure inletport of the compressor; a first evaporator downstream of the vaporgenerator and coupled to the second outlet of the vapor generator; asecond expansion valve positioned between the first evaporator and thevapor generator, wherein the first evaporator is upstream of thecompressor and is coupled to a low-pressure inlet port of thecompressor; a heat exchanger having a first region and a second region,wherein the first region of the heat exchanger is positioned between thesecond outlet of the vapor generator and the second expansion valve,wherein the first region of the heat exchanger is plumbed in series withthe second region of the vapor generator such that an inlet of the firstregion of the heat exchanger is directly coupled to an outlet of thesecond region of the vapor generator, wherein an inlet of the secondregion of the heat exchanger is positioned downstream of the firstevaporator, wherein an outlet of the second region of the heat exchangeris positioned upstream of the low-pressure inlet port of the compressor;a second evaporator downstream of the vapor generator and coupled to thesecond outlet of the vapor generator, wherein the second evaporator isplumbed in parallel to the first evaporator, and wherein an inlet of thesecond region of the heat exchanger is positioned downstream of thesecond evaporator; and a third expansion valve positioned between thesecond evaporator and the vapor generator, wherein the third expansionvalve is plumbed in parallel to the second expansion valve.
 16. The heatpump of claim 15, further comprising: a bypass loop having an inlet andan outlet, wherein the bypass loop is configured to bypass the secondregion of the heat exchanger, and wherein the inlet of the bypass loopis positioned immediately upstream of the second region of the heatexchanger.
 17. The heat pump of claim 16, wherein the outlet of thebypass loop is positioned immediately upstream of the low-pressure inletport of the compressor.
 18. The heat pump of claim 16, wherein thebypass loop comprises a shutoff valve positioned between the inlet ofthe bypass loop and the outlet of the bypass loop.
 19. The heat pump ofclaim 15, further comprising: an auxiliary refrigerant loop, wherein theauxiliary refrigerant loop comprises: an auxiliary compressor; anauxiliary condenser downstream of the auxiliary compressor and coupledto an outlet port of the auxiliary compressor; an auxiliary expansionvalve downstream of the auxiliary condenser; and an auxiliary evaporatordownstream of the auxiliary expansion valve and coupled to the auxiliaryexpansion valve, wherein the auxiliary evaporator is upstream of theauxiliary compressor and is coupled to a low-pressure inlet port of theauxiliary compressor.
 20. The heat pump of claim 19, further comprising:an auxiliary receiver-dryer positioned downstream of the auxiliarycondenser, wherein the auxiliary receiver-dryer is positioned upstreamof the auxiliary evaporator.